Fix for AVIs that have junk frames before the first real video frame
Fix for AVIs that have junk frames before the first real video frame

MaddTheSane/perian,MaddTheSane/perian,MaddTheSane/perian,MaddTheSane/perian,JanX2/Perian,JanX2/Perian,JanX2/Perian,JanX2/Perian,MaddTheSane/perian,MaddTheSane/perian,JanX2/Perian